Write integration tests

[Varunram]

Right now, we only have unit tests for components that are isolated in function from the others. For components who functionality is linked closely with others, unit tests can't help since one needs the other. For this, we would need to have integration tests that test the investment workflow, payback workflow, etc.

[Varunram]

Openx test suite was fixed by recent commits, integration tests between openx and opensolar still remain.